ABSTRACT

Field experiments were conducted during the 2006 and 2007 cropping seasons at the National Horticultural Research Institute Mbato Okigwe, to determine the Influence of lime rates on weeds and yield in six medium maturing soybean varieties (TG x 1440 — 1E, TG x 1444-1E, TG x 1448-2E, TG x 1740 -iF, TG x 1844-18E and TG x 923-2E). In each year, the experiment was laid out as a split —plot in a randomized complete block design with three replicates. Five lime rates of 0, 0.45, 0.90, 1.35, 1.80 and 2.25 t/ha were the main plots, while six soybean varieties were the sub- plots. Data was obtained on weed density and biomass, while yield and associated traits were obtained from six plants on each plot. Uming in 2006 was observed to be highly significant in terms of seed yield in soybean. Significant effects were also observed for varietal effect and interaction for seed yield in the same year but only the varietal effect was significant in 2007. The yield performance of the soybean varieties was not consistent in the two years but it was observed that on the average TG x 1844-18E performed better than the other varieties. Correlation analysis showed that weed density and biomass were negatively correlated with yield while number of leaves, number of pods, leaf area, leaf area index, and seed weight were positively and significantly correlated with yield. These results showed that selecting these attributes will ultimately lead to an increase in seed yield in soybean.